an octopus dies after only a week: comments?

I purchased an octopus about a week ago. This is my third octopus in a year, all in the same tank. That is, it is a mature tank. The first octopus lasted a few months; the second, about 6 months. This one lasted a week. Sigh.

I'd like to figure out what went wrong before I buy another. The tank is a 75 gallon tank which uses a Fluval, even though the tank has an overflow built in. There is a lot of macro algae, which helps.

I can think of a variety of reasons why the octopus may have died:

1) I put two serpent stars in the tank with him. They never seemed to attack each other, but the stars did take up some of the under-rock areas that the octopus seemed to like. Maybe they chased him out of his hiding holes. I guess I should remove them from the tank before I get another octopus.

2) The day before he died, he managed to find his way into the tank's overflow, where it was nice and dark. There was only about 3" of water in the unused overflow, so I filled it up with salt water, so he could get out easily. He never did: the next morning, he was dead. Maybe he was sick, and was going to die anyway, or maybe he suffocatedin the uncirculated water. I tried to get him out, but he was pretty determined to stay in there. I'm manufacturing a plug for the overflow now.

3) Unlike the other two octopuses (who wandered all over the tank a few times each day), this one was VERY reclusive. Maybe he was sick, or maybe he was shy.

4) I had an infestation of bristle worms before I bought the latest octopus, and I solved this dilemma by taking the three live rocks out of the tank and soaking them in fresh water for 2 hours before restoring them to the tank. This did kill the bristle worms, but it may also have killed some of the beneficial bacteria. There is a lot of substrate in the tank, so there would have been plenty of surface area for other sources of bacteria.

Any thoughts about what I did wrong? Should I wait a few weeks and try again?

after working in the exotic animal trade for over twenty years, this is something you unfortunately have to get used to...not fun, and each time I lose a specimen, I feel guilty. But, I don't think you made any mistakes, soaking the live rock is not a problem, and I don't think you need to block your overflow. Perhaps there are not enough dark areas in your tank?

There were three large pieces of live rock, with holes in them large enough for the other octopuses to peer out of, and with "caves" under the rock in which even the most recent octopus resided. I think that base was covered.

it sometimes happens. it could have been stress from shipping/catching etc... maybe it got chilled in the box? Maybe it was a poorly specimen in the first place? Its just one of those things!

I have had octopuses arrive either DOA or die shorlty afterwards!

Some places may offer a refund?

Regarding bristleworms, they actually help a lot in an octo tank since the octos are such messy feeders! I welcome them into my tanks and as they are a sign of overfeeding use them to determine tank health. So next time just leave them there.

Submerging the live rock in freshwater will certainly have killed an amount of the bacteria and is not reccomended.

Anyway, dont be put off, it could just have been bad luck, do some water tests though just to make sure.

I had over 100 bristle worms, some of them 2" long and 1/4" in diameter, in a 75 gallon tank. They filled the rocks, to the point where the octos were unwilling to "sleep" in the rocks. They just hung out on the surface of the rocks.

Then, I bought a very small octo (body would fit under a nickel), and began to fear that he would be caught in a hole in a rock, and eaten.

I understand your point about knowing that overfeeding is occuring, but I already knew that (pieces of shrimp still there the next morning).

What makes you think that bristle worms would not make the rocks less comfortable for an octo?

Ewww, that is a lot of worms. I still would just chalk this octo up to bad luck. THings happen, it could have something to do with the manner in which it was collected added with the stress of getting stuck in the overflow. Did you ever say what kind of octo it was and where it came from? That info could be helpful. I would try to get rid of those worms first before you get another octo. I'm not sure how I would get all those guys out though. Have you checked all your water parameters lately? Just curious.

Things happen, it could have something to do with the manner in which it was collected added with the stress of getting stuck in the overflow.

It was never "stuck" in the overflow. It went in there of it's own volition. The water level was within 1/2" of the top, so it could have gone back had it wanted to

Did you ever say what kind of octo it was and where it came from?

From FishSupply. They've been great before. They had it for 2 weeks before they shipped it to me, so it was probably in decent shape. Probably a bimac. It had two fake eye spots on its body that it would flash black and white. It was quite pretty. Sigh.

I would try to get rid of those worms first before you get another octo. I'm not sure how I would get all those guys out though.

The worms are long gone, weeks ago, using the approach of soaking the rocks in air and in fresh water. All gone. It was really easy.

Have you checked all your water parameters lately? Just curious.

Nope, but my experience is that established tanks rarely get out of whack. I check salinity, add buffer, and don't worry too much.

lol, and i thought it was impossable to kill them B.worms, mine must have been godly. I did notice that you said you only pulled out 3 peices of live rock, is that all that is in there for rocks? 3 peices of live rock in a 75 gallon tank does not sound like alot of hideing area.

Two of the "pieces" of live rock are too large to pick up with one hand. A full grown bimac was able to hide easily inside the holes in one of the rocks, and I make sure that there are "caves" under the rocks and above the substrate. I now have three baby bimacs (from Chris Shaw) living in the 75 gallon tank, and each one has a separate "den" to which they return every night (I do a "bed check"). And some jumbles of smaller rocks. I don't think that this is a problem. And the fact that the three babies have been happy for a month or so is another indicator that the tank itself is OK.